The present invention relates to a process of synthesizing compounds that are useful in the manufacture of carbapenem side chains. These carbapenem antibiotic compounds are effective in the treatment of infections caused by susceptible bacterial organisms.
In the past, the synthesis of appropriately substituted hydroxyprolines has been conducted in the presence of a mixture of carbon tetrachloride, an amine base, e. g., triethylamine, water and an inert organic cosolvent, e.g., ethanol. See, e.g., Synthesis, 1988: 444-448. This process is somewhat undesirable in that it uses excess amounts of reagents and it uses and generates chlorinated hydrocarbons. The present invention utilizes stoichiometric amounts of more economical reagents and generates little undesirable side products.